How your brain handles terror scares

A New York police officer stands at the scene of a suspected bomb contained in a UPS package at a bank in Brooklyn today.

Today's reports of suspicious packages sent from Yemen can add a real-life fear factor to the fictional scares that folks typically experience during Halloween weekend. Whether the scares are make-believe or real, neuroscience provides some strategies for channeling our fear response in the right way.

Millions of years of evolution have optimized our brains' hard wiring to cope with immediate threats -- such as the predators that crossed paths with our ancestors in Africa, said Andreas Keil, a psychologist at the NIMH Center for the Study of Emotion and Attention at the University of Florida.

"Today, we rarely experience the lions that want to eat us, or snakes that want to kill us ... but we respond a lot to cues where somebody tells us through a newspaper article or a Twitter tweet that a threat is around," Keil told me. "The brain's response to those cues is a lot like the response to the real thing."

Acute vs. chronic stressSuccessfully coping with a stressful episode actually produces rewards in the brain, said Ki Ann Goosens, a neuroscientist at MIT's McGovern Institute for Brain Research who specializes in the study of fear, anxiety and stress. "It's good to be in a state of moderate arousal," she said. "That can actually enhance your ability to perform."

In contrast, chronic stress is bad for the brain. "Unfortunately, there's less known about the effects of chronic stress," Goosens told me. "The effects that it has on the cells of the brain aren't uniform. For a lot of the cells in the brain, their function is impaired. You can cause atrophy of cells in the brain."

One of the targets of chronic stress is the hippocampus, the area of the brain that plays a key role in managing memory. "You can imagine that if you have atrophy in this structure, often it's associated with memory impairment," Goosens said. But chronic stress actually causes the opposite response in a different part of the brain, known as the amygdala. Stress boosts activity in the amygdala.

Goosens' lab is focusing on the health effects of long-lasting stress -- effects that appear to range from cardiovascular disease to mental disorders.

"If you're someone who's never been diagnosed with a mental illness, but you have a genetic predisposition for, let's say, bipolar disorder, and you experience a strong, lasting stressor -- for example, someone in your family dies -- then there's a higher likelihood that the illness would be triggered," she said. "Or if you're somebody who has been diagnosed, then you're more likely to start showing symptoms of mania or depression."

Controlling the fear responseSo what does all this have to do with terrorism alerts? Our brains and our bodies are better-equipped to handle well-defined threats that come along with an action plan and a sense of resolution.

"It's best to think about these fear episodes as networks that belong together in the brain," Keil said, "and one thing that goes with the fear response is to have an action plan. If I have no action plan, that will change the way the brain responds to the threat. ... The response is more unpleasant."

That may be why so many people find scary movies and Halloween-style frights to be absolutely pleasurable. Such experiences let people experience the chemical high that goes along with the fear response, in a safe and controlled environment. In such a situation, it's easy to know what to do. "The action plan is to sit there and eat popcorn while the zombies are wreaking havoc," Keil said.

In a way, the make-believe scares serve as "practice runs" for coping with real-life dangers -- and if they're handled in the right way, terrorism alerts can provide similar opportunities for visualizing how to deal with an immediate threat. "I get the benefit of the tickling of my fear system, but at all times I'm in control of my fear response," Keil said.

The action plan is an important part of the process.

"With a terror alert, what are you going to be doing?" Keil said. "When an alert doesn't come with a recommendation for what people shoud do, there's a vague fear that's less appropriate and less functional."

Even if the authorities don't provide those recommendations, it's a good idea to take the opportunity to review your own personal emergency response plan. "That's so in line with common sense you don't even have to ask a brain scientist," Keil said.

Goosens has another piece of common-sense advice: Don't fret alone. Being part of a group makes it easier to cope with fear -- whether it's stimulated by a visit to a haunted house or an actual terror threat. "That reduces your stress response while you're exposed to the threat, and when you're being social, you're activationg parts of your brain that are associated with reward," she said. "One of the things about people who are exposed to chronic stress is that they often exhibit social withdrawal or abnormal social interaction."

Filling in the gapsRisk consultant David Ropeik -- a former msnbc.com contributor whose most recent book is titled "How Risky Is it, Really?" -- said that it's important for government officials and news media to fill in the gaps in information about a threat as fully as they can.

"The psychological effect is called 'representativeness bias,'" he told me. "We take partial information, and when we don't have more, we fit that information itno the pattern that we already know and seems to make sense. Yemen? Ding-ding-ding-ding. Possibly explosive? Ding-ding-ding-ding. It's a mental shortcut that we use to make decisions about whether we're in danger."

That effect meshes perfectly with our hard-wired response to perceived threats. Hundreds of thousands of years ago, the hominids who were careful about keeping their distance from an unknown creature usually fared better than those who blithely walked into the predator's lair. But if the information gaps aren't eventually filled in, there could be negative consequences, particularly in a modern global society.

"If the pattern forms in our minds, that Muslims are dangerous and that chemicals are dangerous, and if we don't find out the truth about all that, then we're left with that pattern. Everything fits the pattern, so we have Islamophobia and all sorts of stereotypes," Ropeik said. "The government and the media need to take more responsibility for clarifying those scary circumstances that, down the road, turn out not to fit the pattern. Because the more we have a pattern in our mind, the more it binds us to irrational representativeness bias. And that's bad for our health."

What do you think? Is the news a source of chronic stress? Do you feel as if the gaps in our information about terror threats are being closed? Is there a psychological benefit to putting real-world worries aside and watching "Saw 3D" instead? Feel free to weigh in with your comments below.